In the rear of the Knight of Newts module some lettered locations are referenced that are supposed to match up to the DM's map. Neither the PDF nor the print copy I have seem to have any such letters; I imagine they were just left off.

In one place it's implied that these are all somewhere in the large room with the "foliage", and that players would have to dive to find them, but some of them sound like they'd be somewhere else (for instance, the spider web).

They aren't in the descriptions I guess because they aren't used in DM-less play.